Abstract 136: The Effect Of Mechanical Chest Compression Device On Survival After Out-of-hospital Cardiac Arrest According To Patient Transport Interval: A Multicenter Observational Study

Abstract

Objectives: This study aimed to investigate the effect of mechanical chest compression device (MCPRD) on patients with OHCA according to patient transport interval (PTI). We hypothesized that MCPRD is effective on survival with prolonged PTI compared with manual chest compression (non-MCPRD). Methods: This cross-sectional multicenter observational study used the Korean Cardiac Arrest Research Consortium registry data from 2015 to 2019. Emergency medical service (EMS) treated OHCAs presumed of cardiac etiology without return of spontaneous circulation (ROSC) at scene were included. Exposure was prehospital MCPRD use and PTI. The main outcome was survival to admission. PTI was categorized into three groups; short PTI for 0-5 minutes, intermediate for 6-10 minutes and long PTI for over 10 minutes, respectively. Multivariable logistic regression was performed to estimate the adjusted odds ratios (AORs) and its’ corresponding 95% confidence intervals (95% CI) for the effect of MCPRD compared with manual compression on outcome. Interaction of PTI on the effect of MCPRD on outcome were tested. To control for selection bias and confounding factors, propensity score (PS) matched cohort was extracted. PS score for each patient to receive MCPRD was estimated using a multivariable logistic regression model. To reduce the standard error of MCPRD on outcomes, a two-to-one propensity score matched cohort was extracted. Results: For unmatched cohort, a total of 3,530 patients were eligible and after PS matching, a total of 2,049 patients were eligible for the analysis. The MCPRD was applied at 19.3% of all unmatched cohort. After adjusting for potential confounders, the AOR of MCPRD for survival to admission was 1.36 (95% CI 1.07-1.72) for unmatched cohort and 1.37 (95% CI 1.06-1.78) for PS matched cohort. Interaction according to PTI on the effect of MCPRD was significant at prolonged PTI on both cohorts; AOR 1.60 (95% CI 1.06-2.42) for unmatched cohort and AOR 1.60 (95% CI 1.06-2.42) for PS matched cohort, respectively. Conclusion : For patients with OHCA with PTI longer than 10 minutes, MCPRD use showed a significant survival benefit compared with manual chest compressions. Further studies are needed to evaluate the appropriate use of MCPRD in special situations.